客户提供了 mysql 的环境，但是不支持中文，通过以下命令查看了 mysql 的字符集
mysql> show variables like 'character_set%';
显示如下：
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | latin1 |
| character_set_connection | latin1 |
| character_set_database | latin1 |
| character_set_filesystem | binary |
| character_set_results | latin1 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
为了让 mysql 支持中文，需要把字符集改变成 utf8 。
方法如下：
1. 打开 etc/my.cnf
2. 修改成如下内容，保存
[client]
port=3306
socket=/var/lib/mysql/mysql.sock
default-character-set=utf8 [mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
character-set-server=utf8 [mysql]
no-auto-rehash
default-character-set=utf8 [mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
3. 重启 mysql 服务
service mysqld restart
再次查看 mysql 编码，已经更新成如下信息
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+